The present invention relates to a laser line beam emitting apparatus, which is utilized for production of a vertical reference line drawn on a floor, a ceiling, and wall(s), and/or horizontal reference line drawn on wall(s), for, e.g., provision of a partition to divide a room. Particularly, the present invention relates to a laser line beam emitting apparatus having a mechanism for automatic location of a tilted laser unit holder to a desired position.
Nowadays, the construction industry uses the laser line beam emitting apparatus in place of the marking (or ink pad) technique, which carpenters or construction workers measure the objectives by drawing a vertical or horizontal line on respective surfaces with a Chinese ink or chalk.
The laser line beam emitting apparatus performs emission of a vertical line beam passing a ceiling above and walls around it or a horizontal line passing walls around it.
For the carpenters or construction workers, such the linear light is a reference line, which allows for, for example, righting of a partition for division of a room.
The foregoing laser line beam emitting apparatus has a laser beam source, a collimator lens and a cylindrical road lenses allow for production of vertical or horizontal line beam from the laser line beam which of elliptical section. The vertical, and horizontal line beams are produced by the cylindrical rod lenses having axes level with, or plumb from the earth, respectively.
Such the laser line beam emitting apparatus has a laser unit in which a laser beam source and the collimator and cylindrical lenses are held. The apparatus has a gimbals mechanism by which a laser unit holder with the laser unit mounted thereto is held, and thus prevents tilting of the laser unit holder from its predetermined position or with respect to the desired angle where allows for accurate emission of the vertical or horizontal beam. Generally, for the prevention of tilting of the foregoing laser unit holder, the conventional laser line beams emitting apparatus has a passive construction such as gimbals mechanism by which the laser unit holder is held.
Alternatively, a conventional laser line beam emitting apparatus has a laser unit holder or laser head having a cylindrical lens and so on. It has an active construction such as the laser unit holder or laser head itself being controlled.
FIG. 5 shows, as an example of the prevention of tilting of the laser unit holder according to the conventional active control, a gyro mechanism having two drives. Such the two drives comprise respective motors, and shafts of the motors are at right to each other such that a laser unit holder 1 turns in directions parallel and perpendicular to a paper on which the drawing is shown. The laser unit holder 1 has two pins radially externally extending therefrom.
The first motor 3 is provided with a screw 4 formed on its leading shaft, the screw 4 has an engagement with a nut 5, and the nut 5 has folk parts 6 extending therefrom. The first pin 2 of the holder 1 has fitting between the folk parts 6. Hence, when turns of the screw 4 moves the nut 5 in a direction longitudinally of the screw 4, the folk parts 6 also move the first pin 2 in a direction longitudinally of the screw 4 so as to give the laser unit holder turn about a first shaft (not shown).
The second motor (not shown), which is of the same type as the first motor 3, gives the laser unit holder turn about a second shaft (not shown) passing an axis orthogonal to the foregoing fist shaft.
Such the conventional laser line beam emitting apparatus has a level sensor for detecting the tilted laser unit holder with respect to the predetermined position so as to output the detection for control of turns of respective first and second motors. Therefore, the retention of the oriented laser unit holder without tilt with respect to the desired angle is always made.
As an example, JP 11-176924, A discloses a laser line beam emitting apparatus which is of an active construction for prevention of tilt of a laser head. The apparatus has drive means which comprise two motors, a level sensor for sensing no horizontally thereof with respect to the vertical direction, and a signal processing circuit for controlling respective motors. The controlled motors orient the laser head in the direction of X and Y axis in accordance with the sensing of no horizontality by the level sensor, and thus the laser head is positioned at the predetermined location.
JP 11-311516, A is also given as example of a laser line beam emitting apparatus like the foregoing construction.
For the prevention of tilting of the laser source unit according to other prior arts except for the foregoing construction, a laser line beam emitting apparatus has a tripod having gotten long and short through its screw. As an idea, a motor gives the screw of the tripod turn, a level sensor controls the turn of the motor, and thus the retention of the oriented laser unit holder without tilt with respect to the desired angle is performed.
In the conventional laser line beam emitting apparatus which is of passive retention of the oriented laser unit holder in the desired location, both of the levelness and plumbness of the produced laser line beam depend on sensitivity of the gimbals mechanism. Therefore, if the gimbals mechanism has higher mechanical resistance, it is difficult to obtain a precisely horizontally or vertically drawn laser line beam. The solution requires technically skilled adjustment of sensitivity. It also requires provision of a high precise and expensive bearing with higher shock and wear resistance to the gimbals mechanism, because of the laser unit holder throwing high load on the bearing.
On the other hand, in the active retention of the oriented laser unit holder in the desired location by control of the two motors, correction for tilting of the laser unit holder is performed by a combination of the level sensor for detecting the tilting for output of signals, and the motors for giving the screw turns for movement of the laser unit holder in accordance with the output signals. In this case, required time from the detection of tilting to the corrected location is too long, since movement of the laser unit holder is given by the screws turning through a motor. Such the laser line beam emitting apparatus has a slow response to tilting of the laser unit holder with respect to the desired location, and thus does not go over construction sites where it is roughly handled and which desire the quick operations.
In order to accomplish solution of the foregoing problems as caused by prior arts, the present invention provides as its objects a laser line beam emitting apparatus having a mechanism for automatic precise location of the tilted laser unit holder to a desired position. The laser line beam emitting apparatus according to the present invention allows elimination of difficulty in obtainment of a horizontally or vertically drawn laser line beam as caused by the conventional one, and has no requirement of the skilled adjustment of sensitivity, and adoption of the expensive bearing.
In addition, the foregoing mechanism of the laser line beam emitting apparatus according to the present invention can have accommodation of rough handling and quick operations, preferable to construction sites.
The laser line beam emitting apparatus according to the present invention may have double adjustment of location of the laser unit holder to the desired position which allows production of laser line beam(s) with precise level and plumb emission with respect to the earth.
The first adjustment, which is rough one, is performed by use of conventional gimbals mechanism by which the laser unit holder is held. The second adjustment, which is fine one, is performed by a level sensor and a device for generation of thrust.
The level sensor comprises a casing, a laser diode, a collimator lens, a reservoir with liquid and bubble at the center thereof, and a photo acceptance unit. The level sensor is mounted to the laser unit holder such that its components are arranged in series from down to up therein. A level sensor as disclosed by JP 11-176924, A or JP 11-311516, A may be employed.
The level sensor may sense the tilting of the laser unit holder through laser beam(s) emitted from the laser diode and collimated through the collimator lens. When the laser unit holder is tilted, the collimated, emitted laser beam(s) reach a position distant from the center of the photo acceptance unit because of refraction by the bubble in the reservoir. Resultant tilting signals from the photo acceptance unit are outputted to the device for generation of thrust.
The device for generation of thrust comprises at least one magnet, and a plurality of coils, and performs maintained location of the laser unit holder to the desired position in accordance with conduction to the coils, controlled by the output signals from the level sensor.
The laser line beam emitting apparatus according to the present invention may have a gimbals mechanism having a laser unit holder swingy held by respective shafts thereof orthogonal to each other. In this case, the device for generation of thrust gives bidirectional thrusts such that each of the laser unit holder swings in respective directions of elimination of the tilting.
Such the device for generation of thrust has a first coil which comprises a coil for generation of thrust going to one direction, a second coil which comprises a plurality of coils for generation of thrust going to another direction, and a magnet causing magnetic flux to be produced such that the thrusts pass across respective first and second coils.
According to the present invention, the magnet of the device for generation of thrust is provided to the base of the laser line beam emitting apparatus, while both of the first and second coils are provided to the laser unit holder.
Alternatively, the former is provided to the base of the laser line beam emitting apparatus, while the latters are provided to the laser unit holder.
Such the coil in use for the thrust generator includes not only a winding coil as reminded of the wound conductive wire, but also a printed coil substrate comprising a substrate with one or more layers, and a conductive material printed in a form of a winding pattern on or in respective substrates.
In this case, both or one of the first and second coils may be of printed coils, respectively. In addition, when both of the first and second coils are of respective printed coils for provision of the generated thrust in both of the forgoing directions, a single substrate may have both of the winding patterns of respective first and second coils. The device for generation of thrust has no limitation in the number of the winding pattern, with the generated thrust for position of the laser unit holder to the desired location.
In other words, the printed coil substrate according to the present invention may be constructed by ones disclosed in e.g. U.S. Pat. Nos. 6,281,779, 6,000,128, 5,952,909, 5,521,573, and 5,184,103.
According to the present invention, each of the gimbals mechanism and device for generation of thrust may be of adjustment in corrected location of the laser unit holder in only one direction.
Thus, the maintenance of location of the laser unit holder at the predetermined position by the controlled conduction to the coils and combined magnet of the device for generation of thrust, in accordance with the output signals from the level sensor, allows precisely actively plumbing up and leveling up of the laser unit holder. This eliminates requirement of works to adjust location of the laser unit holder with sensitivity of experienced skills, and permits an inexpensive bearing to be adopted.
Furthermore, a performance of the adjusted location of the laser unit holder by use of the device for generation of thrust which comprises the magnet and coils allows instant operations from the detection of tilting to the elimination of tilting of the laser unit holder. This gives a laser line beam emitting apparatus enough accommodation of use at construction sites and so on having a tendency of the rough handling thereof and a preference of the quick operations thereof.